Warn if no files field in package.json or .npmignore file present

source/cli.js

@@ -72,6 +72,8 @@ updateNotifier({pkg: cli.pkg}).notify();
 (async () => {
 	const pkg = util.readPkg();
 
+	util.checkIgnoreStrategy(pkg);
+
 	const defaultFlags = {
 		cleanup: true,
 		publish: true,

source/util.js

@@ -1,10 +1,13 @@
 'use strict';
+const {existsSync} = require('fs');
+const path = require('path');
 const readPkgUp = require('read-pkg-up');
 const issueRegex = require('issue-regex');
 const terminalLink = require('terminal-link');
 const execa = require('execa');
 const pMemoize = require('p-memoize');
 const ow = require('ow');
+const chalk = require('chalk');
 
 exports.readPkg = () => {
 	const {pkg} = readPkgUp.sync();
@@ -61,3 +64,27 @@ exports.getTagVersionPrefix = pMemoize(async options => {
 		return 'v';
 	}
 });
+
+exports.checkIgnoreStrategy = ({files}) => {
+	const npmignoreExists = existsSync(path.resolve(getRootDir(), '.npmignore'));
+
+	if (!files && !npmignoreExists) {
+		console.log(
+			`\n
+╭───────────────────────────────────────────────────╮
+│                                                   │
+│                 ⚠️  Warning ⚠️                      │
+│   No ${chalk.bold.cyan('files')} field specified in ${chalk.bold.magenta('package.json')}        │
+│   or ${chalk.bold.magenta('.npmignore')} file present in the root folder.  │
+│   Make sure you have either one or the other.     │
+│                                                   │
+╰───────────────────────────────────────────────────╯
+`
+		);
+	}
+};
+
+const getRootDir = () => {
+	const sourceDir = path.dirname(require.main.filename);
+	return path.resolve(sourceDir, '..');
+};